Trailer coupling device and antijackknife control therefor



Oct. 19, 1954 J. H, HAMMOND, JR., ETAL 2,692,145

TRAILER COUPLING DEVICE AND ANTIJACKKNIFE CONTROL THEREFOR Filed 0ct. 25. 1950 36 32 kiwi 4% 3nventor JOHN HA YS' HAMMOND, JR.

I I B ALBERT u. TRENOR.

u a B- K I g 7 (Ittom;

Patented Oct. 19, 1954 TRAILER COUPLING DEVICE AND ANTI- JACKKNIFE CONTROL THEREFOR John Hays Hammond, Jr., and Albert D. Trenor, Gloucester, Mass; said Trenor assignor to said Hammond, Jr.

Application October 23, 1950, Serial No. 191,695

5 Claims.

This invention relates to steering control of trailers and more particularly to means for preventing the jack-knifing of the vehicle.

An object of the invention is to provide means for applying a braking action to the coupling device of a trailer truck when there is a tendency for the trailer to jack-knife while allowing the free action of the coupling device when the relative motion between the trailer and tractor is in the opposite diretcion.

The nature of the invention as to its objects and advantages, the mode of its operation and the manner of its organization, may be better understood by referring to the following description, taken in connection with the accompanying drawing forming a part thereof, in which Fig. l is a schematic view, of a coupling and control mechanism constructed in accordance with the invention showing the coupling device in section taken in the line l-l of Fig. 2, and

Fig. 2 is a side elevation partly in section of the coupling device shown in Fig. 1.

Like reference characters denote like parts in several figures of the drawing.

In the following description parts will be identified by specific names for convenience, but they are intended to be generic in their application to similar parts.

Referring to the accompanying drawings a base plate H is adapted to be mounted on the chassis of a tractor, not shown, in the usual manner. Secured to the base plate II is a pivot pin l2 on which is rotatably mounted a rotary disc [3. Mounted between the disc I3 and base plate II are two circular members I4 and I5 which are secured to the disc l3 by means of rivets l and therefore rotate with the disc [3 about the pin I2.

The member I4 is provided, with wedge shaped slots [6 which slope toward the center in a clockwise direction and the member I is provided with wedge shaped slots I! which slope toward the center in a counterclockwise direction. Located in the slots [6 and H are a plurality of steel balls IB. Rotatably mounted on the members i4 and I5 are two rings 2! and 22, the outside surfaces of which act as brake drums. Surrounding the rings 2| and 22 are two brake bands 23 and 24 which are provided with brake linings 25 and 26 which may be similar to those used in standard automotive equipment.

Secured to the brake band 23 are two cars 21 and 2B and secured to the brake band 24 are two ears 3| and 32. The ears 2'! and 3| are rigidly secured to the base II by means of pins 33 and 34. Pivoted to the ears 28 and 32 are the ends of two piston rods 35 and 36 to the other ends of which are secured pistons 3'! and 38 which reciprocate respectively in cylinders 4| and 42 mounted on the base plate ll. Behind the pistons 3! and 38 are located compression springs 43 and 44 which tend to advance the pistons and rods, thus relieving the pressure on the brake bands.

The forward ends of the cylinders 4| and 42 are connected by pipes 45 and 46 to a rotary valve which consists of a casing 41 and a rotary stem 48 which is provided with grooves 5| and 52. The valve 4'! is also connected to a source of hydraulic fluid under pressure 53 by a supply pipe 54 and a return pipe 55. The valve stem 48 is secured to an arm as which is normally held in a central position by means of balanced springs 56 and 51, the distal ends of which are anchored to two pins 58 and 59 mounted on the base plate ll.

Mounted on the base plate I l are two solenoids 6| and 62 the cores 63 and 64 of which are connected by links and 66 to the end of the valve arm 49. One side of the windings of each solenoid 6 land 62 is connected thru a battery 6'! and switch 68 to two flexible contacts H and I2 which are mounted on an insulating base 13 secured to a bracket 14 in which the steering column 15 of the tractor is supported. Mounted on two blocks of insulation 16 and 11 are two fixed contacts l8 and 19 which at suitable times are engaged by the flexible contacts I! and 12. The fixed contacts '58 and 19 are connected respectively to the other sides of the windings of the solenoids 6i and t2.

Rotatably mounted on the steering column 15 is a split member 8| provided at one end with an arm 82 and at the split end with two lugs 83 and B4. Passing thru the lugs 83 and 84 is a bolt 85 provided with a nut 86 between which and the lug 84 is a compression spring 8'1. Secured to the inner surface of the split member 8| is a band of friction material 88 which engages the surface of the steering column 15. Mounted on the base plate II are two pins 91 and 92 which act as stops for the arm 82.

Mounted on the disc I3 is any standard type of coupling device 93. This for example may be of the type known as the Holland-Apgar Safety Fifth wheel made by the Holland Hitch Co. of Holland, Mich. In this type of coupling a lower bearing plate 94 is mounted on a rocking shaft 95 which rotates in bearings 96 secured to the disc IS. The lower bearing plate 94 is provided with spring mounted keys Bl which lock the lower bearing plate 94 to the upper bearing plate of the trailer (not shown) in a well known manner. A lever 98 is provided for operating the keys 91.

Mounted on but insulated from the base plate II are two segmental contacts IOI and I02 which are electrically connected to one side of the windings of the solenoids GI and 62 by leads IOIa and H121; respectively. Mounted between the segmental contacts IOI and I02 is a segment of insulation I03. If desired the extent of spacing l between the segments WI and I02 may "be varied by making these segments adjustable in any well known manner. Engaging the segment of. in sulation 103 is a contact arm I04 which is mounted on an insulated bracket I secured to the disc I3 in any suitable manner not shown. The contact arm I04 is electrically connected Joy 2. lead I 06a thru a switch I06 to one side of the battery 61.

Operation In the operation of the .form of the invention shown in the accompanying figures the upper and lower bearing plates of the trailer and tractor are locked together in the usual manner and thelreys 9'! are moved into an operative position .by means of the lever 98. Inthis way the upper and lower bearing plates rotate together about ,the pivot pin l2 as the trailer swings tothe right and left of the tractor in normal driving. As llong :as the switch :68 is .open the swinging is runhampered, as the brake bands 23 and 24 are .free from the rings 2I and 22.

when going down a steep hill .or on icy roads the :driver of the truck closes the switch 8, which '.may be'located in the cab of the tractor. If the :truck should go out of control and start to jack-- knife. so that the tractor swings in a counterclockwise direction or to the left with respect to .the trailer, the driver would naturally turn .the steering wheel to the right to straighten out the vehicle .thus rotating the steering :colunm in a clockwise direction. This motion causes the split ,memherfll to rotate in a clockwise direction, .due

ito'the friction of the hand 88 on the steering vcol- .75,'thus moving the arm .82 to the right until it engages the stop 92. In its travel the arm 82 engages the flexible contact '12 and shifts I it intoengagement with the fixed contact 19, thus energizing the solenoid 62 which my means of its core 64 and link 65, moves .the arm 49 to the left. causes :the valve stem :48 to be rotated :a

small amount in .a counter-clockwise direction,

thus connecting the groove 5| with thepipe and allowing fluid :under pressure to pass from the :supply source53 to the cylinder M. 4 -5-the piston 31 to retract and :tighten the brake This causes band 2.3, thus locking the ring 2-1 tothe base plate 'II.

if the jack-knife action .coninnues there will .be a tendency for the ring 21 which is now locked to the tractor chassis, to rotate in .a counterclockwise direction with respect to the circular member M which is locked .to the trailer thru the 7,

coupling. As soon as this relative motion starts. however, the balls I8 will roll in the wedged shaped slots 1-6 so as to act as a clutch-between the circular member .14 and the 2|, thus steering wheel the relative motion between the ring 2| and the circular member I4 is reversed and the balls I8 will roll in a clockwise direction, thus. releasing the clutching action.

If the vehicle tends to jack-knife to the right a similar but reverse action will take place. The

steering wheel being turned to the left will swing the arm 82 to the left, closingthe contacts I I--'I8 and energizing the solenoid 6| to rotate the valve stem 48 in a clockwise direction and allow fluid to enter'the cylinder 42 thus tightening the brake loand24 which will lock the ring 22 to the plate I I.

Then any more tendency to jack-knife to the right will produce a relative motion in a clockwise direction between the ring 22 and the circular member I5 causing the balls I8 to roll in the grooves I! so as to clutch the ring 22 to the circular member I5 and thus prevent any further jack-knifing. As the vehicle returns to a straight ahead position, the relative motion .be-

tween/the ring 22 and the member I5 is reversed and the clutching action ceases.

If it is desired to have the degree of angular motion between the tractor and trailer control the braking action the switch B8 is opened and the switch I06 closed. If, under these conditions, the tractor should swingto the left an amount sufficient for the segmental contact .102 to 'move into contact with the arm I04 a circuit would be closed from the battery 6'1 thru the solenoid 62 which, as previously described, would apply the brake band'23 to the ring 21 thus preventing any further relative motion to the left of the tractor with respect .to the trailer. As soon i as the tractor swung back to'the right the seg- .ment "1102 would move out of engagement with the arm I04 thus deenergizing the solenoid 62 and releasing the brake band 2.3.

If the trailer should swing to the right the opposi'te action would take place and the solenoid "6| would be energized to apply the brake, band 24 to the ring '22 .to prevent .further swinging to the right.

It .is thus seen that by providing two concentric over-riding oppositely acting clutchesbetween the coupling gear and the tractor chassis and by providing braking means to be applied to the outside members of these clutches, it. is .possible to lock the tractor and trailer together so as to prevent or greatly minimize jack-knifing action. It is also seen that when the tractor and trailer tend to return to a normal driving condition the over-riding clutches cease to act and allow a free motion between tractor and trailer.

By the use of this invention it seen that normal driving will be unhampered, but as soon .as the trailer tries to take control away from the tractor the over-riding clutches will come into action and prevent or minimize jack-knifing.

Although only one of the various forms in which this ,inventionmay be embodied have been shown herein, it is to be understood that the invention is not limited to any specific construction but may be embodied in various forms without departing-from the spirit of the, invention.

What is claimed is:

l. A- device for coupling-tractors and trailers, comprising a base member to be fixed to the tractor, a second rnem'bertn'i be fixed to the trailer and rotatably'securedto the base memberto turnwith respect thereto about a verticalaxis, a pair'of oppositely directed clutches coupling said .base. member to said second member, each clutch being selectively engag'eable to lock said second member .in a clockwise direction under the action of the "7 againstrotationalmovement inone direction and to permit free rotational movement in the reverse direction, and means responsive to rotational movement of said second member from in line position beyond a given limit to engage the clutch which is directed to prevent further movement in the same direction whereby the movement of the trailer away from in line position with respect to the tractor is restricted.

2. A device for coupling tractors and trailers, comprising a base member to be fixed to the tractor, a second member to be fixed to the trailer and rotatably secured to the base member to turn with respect thereto about a vertical axis, a pair of oppositely directed clutches coupling said base member to said second member, each clutch being selectively engageable to lock said second member against rotational movement in one direction and to permit free rotational movement in the reverse direction, a steering column for said tractor and remote controlled means responsive to rotational movement of said steering column in a direction to return the tractor and trailer to in line position to engage the one of said clutches which is directed to prevent relative movement away from in line position, but to allow movement toward in line position.

3. A coupling device as claimed in claim 2 in which said clutches comprise rings, inner members having members engaging said rings when said inner members rotate in one direction, but releasable from said rings when said inner members rotate in the other direction, and brake bands selectively locking said rings against rotation in response to said remote controlled means.

4. A coupling device as claimed in claim 3 in which said remote controlled means comprises fluid pressure cylinders having pistons connected to actuate said brake bands, valve means connected to control the flow of fluid to said cylinders, and remote means to actuate said valve means.

5. A coupling device as claimed in claim 4 in which said last means comprises solenoids connected to control said valve means and energized in response to the turning of said steering column.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 903,884 Przygode Nov. 17, 1908 1,238,075 Adams Aug. 28, 1917 2,343,984 Lambert Mar. 14, 1944 2,361,935 French Nov. 7, 1944 

